The spatial and temporal distributions of spheroidal carbonaceous fly-ash particles (SCP) in the sediment records of European mountain lakes

Abstract

Sediment cores were taken from 31 mountain lakes in 11 countries across Europe. For each core a full spheroidal carbonaceous particle (SCP) profile was produced. SCP are derived from the high temperature combustion of fossil-fuels and provide an unambiguous record of the atmospheric deposition of anthropogenic pollutants. The data from the sediment cores were therefore able to show both temporal and spatial trends in pollutant deposition across the continent from Svalbard to southern Spain and from Ireland to the Tatra mountains. In general, the temporal trends throughout Europe were remarkably consistent and were seen to be in good agreement with known historical emissions, combustion figures and modelled historical pollutant patterns for source countries. Spatial patterns showed that highest concentrations and accumulation rates were in central Europe, with clear decreases northwards and southwards from the region. An east to west decrease was also apparent. SCP profiles can be converted to full post-Industrial inventories and normalised against a 210Pb inventory to create a ‘pollution index’ covering the whole of the SCP record. Such indices take into account sediment variability and some catchment influences and are therefore better for inter-site comparisons. These results were seen to show a clear latitudinal pattern, with a maximum at around 50°N and declining to the north and south. This agrees with European sulphur emissions data and are generally consistent with EMEP modelled distribution patterns. In many cases the SCP temporal profiles could only be explained by using emission and combustion statistics from more than one country emphasising the transboundary nature of particulate transport throughout Europe, in general, supporting EMEP modelled ‘blame matrices’.